A third Taiko Drum Master is planned for Wii U, if a URL to the series’ official website is anything to go by.
Visiting wiiu3.taiko-ch.net brings users to a page with the text “wiiu3.taiko-ch.net.” Inserting any other number in place of “3” (outside of 2) results in an error page.
The drumming game series made its Wii U debut with Taiko Drum Master: Wii U Version in 2013. A followup, Taiko Drum Master: Tokumori, launched for the platform in 2014. Before Tokumori‘s announcement, however, the game’s existence was discovered via the URL wiiu2.taiko-ch.net, just like this potential third entry.
If last year’s schedule is to go by, an official announcement should arrive around early September.